1. Field of the Invention
This invention relates to phase shift keying (PSK) modems and in particular to integrated circuit PSK modems employing field effect transistors and switched capacitor filters. More specifically, this invention relates to a PSK modem voltage controlled oscillator (VCO).
2. Description of the Prior Art
Discrete component type VCO's are well known in the prior art. Also, integrated circuit VCO's are well known in the prior art. High speed VCO's require expensive, high-speed operational amplifiers.
High-speed VCO's may be digital type VCO's as employed in the prior art.
This invention uses conventional components to provide a high-speed VCO.